Borehole drilling control system, method and apparatus

Abstract

One embodiment includes an apparatus comprising a steerable well bore drilling tool having a main tool body. The steerable well bore drilling tool includes an inertial measurement unit to output a measurement used to determine an azimuthal deviation and inclination of the steerable well bore drilling tool during a drilling operation.

1. An apparatus comprising:
 a rotary steerable tool having a main tool body having a first end coupled to a bottom hole assembly of a drill string and a second send coupled to a drill bit, the rotary steerable tool comprising an inertial measurement unit to output a measurement used to determine an azimuthal deviation and inclination of the rotary steerable tool during a drilling operation, wherein the rotary steerable tool comprises a shaft comprising a rotating platform on which said inertial measurement unit is positioned, wherein the rotary steerable tool is configured to receive a steering command from a control means at a surface of the Earth to control a direction of drilling a borehole using the rotary steerable tool. 
 
   
   
     2. The apparatus of  claim 1 , wherein the measurement includes an angular rate around a number of orthogonal axes. 
   
   
     3. The apparatus of  claim 2 , wherein the measurement includes a linear acceleration along the number of orthogonal axes. 
   
   
     4. The apparatus of  claim 1 , wherein the inertial measurement unit is to output the measurement independent of a magnetometer measurement. 
   
   
     5. The apparatus of  claim 1 , wherein the inertial measurement unit is to output the measurement that includes a magnetometer measurement. 
   
   
     6. The apparatus of  claim 1 , wherein the rotary steerable tool further comprises an estimation means to estimate a direction of the rotary steerable tool based on an output from the inertial measurement unit. 
   
   
     7. The apparatus of  claim 6 , wherein the inertial measurement unit includes at least one gyroscope to measure angular rate around one or more of the number of orthogonal axes. 
   
   
     8. The apparatus of  claim 7 , wherein the inertial measurement unit includes at least one accelerometer to measure acceleration along one or more of the number of orthogonal axes. 
   
   
     9. The apparatus of  claim 8 , wherein the inertial measurement unit includes an orthogonal triad of linear accelerometers and two dual-axis gyroscopes. 
   
   
     10. The apparatus of  claim 8 , wherein the rotary steerable tool further comprises a bore hole length measurement means to measure the distance of the rotary steerable tool along the bore hole. 
   
   
     11. The apparatus of  claim 10 , wherein the estimation means is to estimate the azimuthal deviation and the inclination of the main tool body based on the angular rate and the acceleration and as a function of the length of the bore hole. 
   
   
     12. A system comprising:
 a drill string that includes a bottom hole assembly; 
 a drill bit coupled to a bottom end of the drill string; and 
 a rotary steerable tool comprising,
 a main tool body having a first end coupled to the bottom hole assembly and a second end coupled to the drill bit; and 
 an inertial measurement unit to output a measurement that includes an angular rate around a number of orthogonal axes and a linear acceleration along the number of orthogonal axes, wherein the measurement is used to determine an angular orientation of the rotary steerable drilling tool during a drilling operation, wherein the inertial measurement tool is positioned on a rotating platform of the rotary steerable tool, wherein the rotary steerable tool is configured to receive a steering command from a control means at a surface of the Earth to control a direction of drilling a borehole using the rotary steerable tool. 
 
 
   
   
     13. The system of  claim 12 , wherein the angular orientation includes an azimuthal deviation and inclination of the rotary steerable tool. 
   
   
     14. The system of  claim 12 , wherein the main tool body comprises a deflection means to deflect the second end away from a longitudinal axis of the main tool body. 
   
   
     15. The system of  claim 14 , wherein the main tool body comprises an estimation means to estimate a direction of the main tool body based on the measurement output by the inertial measurement unit. 
   
   
     16. The system of  claim 12 , wherein the inertial measurement unit is to output the measurement independent of a magnetometer measurement. 
   
   
     17. The system of  claim 12 , wherein the inertial measurement unit is to output the measurement that includes a magnetometer measurement.